An analytical and experimental investigation was performed to study the phenomenon of projectile impact on moving plates. Most of the tests were executed using 0.25" diameter, 1.5" long blunt hard steel cylinders fired by a compressed gas gun to perforate plates with a linear speed of 130 ft/sec. The motion was generated by attachment of targets to an arm mounted on the shaft of a 3/4 hp motor. Velocities of the striker ranged from 160 ft/sec to 1000 ft/sec.

The plates used were composed of 0.030" thick CR1010 steel and 0.031" and 0.063" thick 2024-0 aluminum. The penetration phenomenon was viewed as consisting of plugging and petaling failures and large deflection of the targets. The plugging failure was similar to that found in normal impact on stationary targets except for the inclined periphery of the plugs. The non-axisymmetric petaling failure of the plates was the result of contact with the side of the striker. One major crack along the direction of target motion was always formed in the steel plates for all impact conditions and in the AL plates near the ballistic limit. Two major cracks were manifested in the AL targets as the speed of the projectile increased. The magnitudes of the ultimate tensile strain and deformation of the plates are the major causes for inducing these two types of petaling failure.

A three-stage plugging model involving plastic wave propagation, joint projectile/target motion and tensile (plugging) failure was developed for the case of impact on stationary targets. A membrane theory was adopted for determining the response of the plates. This axisymmetric plugging model was then extended to the case of impact on moving targets using the law of conservation of momentum. Petaling failures were analyzed using an energy approach. Energies dissipated due to modes I and III fracture, plastic stretching in the circumferential direction, curvature changes in the radial direction and momentum change of the petal were included. Projectile motion was calculated using rigid body dynamics.

Comparisons between analytical and experimental results were presented for final projectile linear and rotational velocities, the terminal bullet trajectory and angle of obliquity, and for the plate crater length. Good agreement was found.